The present invention relates to an improved key mechanism for wind instruments, and more particularly relates to an improvement in construction of a key mechanism for woodwinds such as baritone saxophones in which two register holes are simultaneously closed by a lever action on pad cups.
A big and long woodwind such as a baritone saxophone is often provided with two middle tone holes formed in the body in order to enable easy generation of harmonics of the middle tones for rich tone colour effect. In this case, both tone holes have to be closed and opened simultaneously and reliably in order to avoid dull generation of tones. A key mechanism including a pair of pad cups, i.e. hole covers, is in general arranged on the body of a woodwind for control of such action on the tone holes.
Conventionally, such pad cups are mounted to a hinge rod on the body of the woodwind by means of an angled key so that, upon swing of the key caused by axial rotation of the hinge rod, the pad cups should close or open the associated tone holes. With this conventional construction, however, use of a single key for two pad cups is accompanied with several drawbacks. First, possible production error of the pad cups, variation in thickness of soft pads attached to the pad cups and timefunctional change in thickness of the soft pad on each pad cup tend to concur to disenable complete closing of the tone holes, thereby causing air leakage which connects to dull generation of tones. Second, adjustment in thickness of the soft pads and/or in mounting of the pad cups in general requires highly skilled operators and long time, which connect to lowering in productivity.